Trailer relay valve for vacuum brakes



Jan. 15, 1952 N; c; WILLIAMS 2,582,612

TRAILER RELAY VALVE F OR VACUUM BRAKES Filed March 15, 1948 7 s Sheets-Sheet 1 INVENTOR. NORMAN C. WILLIAMS Jan. 15, 1952 N. c. WILLIAMS 2,582,612

' TRAILER RELAY VALVE FOR VACUUM BRAKES FiledMarch 15, 1948 5 Sheets-Sheet 3 INVENTOR. NORMAN c. wpums f/w/cww Patented Jan. 15, 1952 alstzrna memev g-rewvscum 1 ena tments-onus,- 1'9485. SeriaI NoB 145983:

szeiai'in a This invention relates tova trailenrelaysvalve for vacuum brakes. especially asmsed-on haulage vehicles that include: a trawtor and separable trailer, though'it is: useful for unitamytrucks: and other vehiclesot. the heavy type: that re== quire. brakes; I

I Speaking from a strictly technica -viewpoint; vacuum brakes-i are-operated bylair at-atmos phere pressure,- the availableforce---beingethe= difierence' between atmosphere" and the ilower pressure; which is? always somethings aboveas complete vacuum.- Since the truckingaartc re gards the source of: vacuum as the' source oibraking power,- which is indirectly correctflit is thoughtthatthe following; explanatiomwill be far clearer to thoser concerned withthisinvention to treat the vacuum asalpositi-ve stead of a negative'force.

The over-all 1 object of: the:- present inventionis to speed up the =-application-of vacuumbrakes: on a trailer vehicle and to-.-make it' possible: to'-= realizethe max-imumwrakingnefiectin" a; muchv shorter time than canbeHotherwiseexpectedr' It has longbeen'the :practloe: with airbrakes-:- and vacuum brakes alike-,1 to place an'aauxiliaryr reservoir ona trailer vehicle: within--which brake setting energy can: be stored and to make the: energy in such reservoir automatically?available}. either by control-valve'operable byathe idriver or by a break-away-thatadmits-atmosphereepres sure to the conduit:throughwhich the vacuum energy forthe: trailer was:originally-supplied? This mode ofoperation iis still includedwith my; new relay valve, but th'arelayvvalve superposes an additional function th'atisbelievect to be entirely novel and greatlyi s'peeds up'i the api plication of vacuum. brakes' irrthea orderlyima'xr ner of theirapplication by the sm'a riual'valve control- -referred to, m-tuis way::- I

In applying trailer' b'rak'es'i theu'r'iode to, of utilizing the "vacuum-energy erases reservoir'for" initial movenient of' tlfe brake is required, theengine; driven by the loa highly effective vacuum machine:

The reservoir" will be availabl forfbi akeflapfthe reservoir when the brake ep iieateiewni 607 move the brakes into braking.conteetwitfi-itiieir. respective brake drums un'derihfluence rh ai y,- of energy from the reservoir; thusldpletingthe store of energy in. the reservoirematerially'.

is the object of the -relay valve ot 65 nionlinner chamber 9 an atmosphereinterconsource of; energy to restore the reservoir and withit the: actuatedhrakes" to the maximum energy withim the; capacity of theengine,= as" desired by the operator. m 'l he f -unetion is then that when thedesired amount of brake power has been reached; the

per-t leading tothe-reservoir isau-tomatically reopened topermitthe" engine sourceto restore the energy of the reservoir atwhatwe call itsleisure li ravvings aecornpany and form apart or this specification; in; which---- v l Fig. 1 is a side view in elevation of a=preferred formof the-- invention;- V

Fig. z isz a ztransversese'ctionof the structure taken on the plan 2 -2 of Fig. 1;

Fig: 3- is-aseetion-of-Figz -2-,- i-takerron the plane Eige i is al -section taken on' theplane 4:4;-

Fig: 5 a diagram showing-' the structure" of the invention iri the me'dian area with'p'ipes, auxiliary? controls and"- other known structures useir' to form one operative vacuum hrake tra-ilerequipmentwas will be explained; Thereare-several' difierent types of brake systems; With-which the' i'clentical fornrotthe 'invention is" useful; and

Fig. a view 'of the' specialcheck valve that will be explaind hereinafter."

Explain g tlfe iig ur" ir'i greater 'detai-l, not'as tio to-clarify the stru'm ti'i'r'e Here mployed; ni -illustrate the principles and the best structure of the invention itself yet eevemgseu; I

Begifinilig'vv gs; 1 eua "2,-nmnere1 l repre- "th e eapz'? a base-cap 3', and a ruff "thebody'lf all of which; the relatiohshipsho'vvn; a he rfi'etically"tiglitcontainer for valve apparatushereih after described. Thereare severalgpipl cofinection's, namelya, mainenergy -conneeuen 5 an auxiliary. reservoir connection 8,

a hu enaeeuen make applicator ports 3, there being two at opposite ends -of the; com;-

structed that it will remain open to a relatively small volume of air by reason of alight spring bias, but when a large volume of air surges against it, it closes like an ordinary check valve.

Conduit II also contains one of the two hose couplings |2, employed in connecting and disconnectin a trailer from the tractor, and conduit 46 serves to connect conduit L te-port. l0.

Vacuum energy in this illustration is shown as derived from the manifold I5, which'is' connected by the conduit IE to the conduit II, and

of necessity contains a closed type checkvalve l7, another well known instrument to the brake art. I

The conduits 80 and Marc connected to the ports'a on the relay valve of'the invention and serve the purpose'of controlling the brake'applicators, all numbered I8 since they'are identical and well known. One of the applicators has-been brokenaway in part to show the diaphragm I9, which, with the pull-rod 20, works concurrently to set brakes on a brake drum.

Both instruments are shown in full release position. r

Numeral 2 I represents the well known auxiliary reservoir connected by conduit 35 to the relay valve of the invention at the port 6. Conduit 22 is an air inlet pipe connected to port I of the relay valve and serves to admit atmosphere pressure, to apply brakes, or vacuum to release the brakes, when-the lever I4 is properly moved, and

contains the other hose coupling- |2, previously mentioned.

The relay valve itself and how it operates underdififerent conditions will now be explained.

On top of the cap 2, is a port 23, to which is applied an air cleaner 24, through which atmosphere can enter to release the brakes when such action is required. When atmosphere pressure exists on both sides of the diaphragm 25, the natural springiness of the diaphragm is biased to release position as shown in Figs. 3 and 4.

When equal atmosphere pressure exists in the chambers 23, 28, 29, 30, 9 and 3|, the brakes are in full release position and the valve parts are as shown in Figs. 3 and 4, no vacuum energy present in any part of the brake system. When vacuum is establishedin chamber 26 and concurrently in chambers30 and 3|, with atmos-x phere pressure in chambers 9 and 29, the brakes are likewise in full release. The diaphragm 25 is annular, with the center spanned by a bridge Chamber 25 is a main suction energy chamber deriving the energy from the engine manifold I; 28 is the auxiliary reservoir chamber; 29 is the atmosphere chamber, always connected to aterators l8 in communication with suction means, the main energy chamber 28 and the auxiliary reservoiril to set the brakes. It is thus seen that chamber 30 is properly named the brake setting chamber.

A diaphragm 32, is responsive to atmosphere pressure in" chamber 29 to'push the valve stem 27' downward to open the pilot valve 33 when vacuum is admitted to chamber 26. Diaphragm 32, having greater effective area than that of the pilot valve-33, causes 33 to leave its seat 43,

thus relieving the heavy load on the main valve 34, which permits it to drop free of its seat 44, admitting full vacuum energy conditions into chamber 28,whereby vacuum is established in the conduit 35,"and the auxiliary reservoir 2|.

, This vacuum energy condition originates in the manifold I5 and is applied through conduit I3 mosphere; is a vacuum chamber, employed,

to displace atmosphere from the upper side of overcoming it, close the valve 39 and open valve thus chamber 9 is the common terminus of conduits 80 and 8| to place all of the brake opto conduit H and to control valve |3, and, when lever M is in release position, to conduit 22, whic represents normal driving condition.

To apply brakes,- the degree of application being controlled by-the lever|4, the amount of atmosphere needed is supplied through conduit 22 to the chamber 3|.- The diaphragm 36, operating under influence of admitted atmosphere, against the stem 31 and its plate-like head, causes stem 31 to rise against stem 2|-With which it is telescoped, a form of-lost motion device. As stem 2! is moved upward, valve 34 and pilot valve 33 are moved upward toward their seats 44 and 43 respectively by the influence of spring 42. As the stems 31 and 21 are moved upward, they lift the cage assembly 38, and close chamber 29 from chamber 9 by lifting the annular valve seat 33,'

a part of the cage assembly 38, against the poppet valve 40, made integral with diaphragm 32, thus lifting poppet valve 40 from seat 45, placing chamber 9 in direct communication with the vacuumenergy sources through chamber 28.-

Stem 21 is of sufficient length that poppet valve 40 must leave seat before valves 34 and 33 can completely close, however, as chamber 26 is opened to communication with chamber 9, conduits 8|] and 8|, and brake applicators l8, the atmosphere present in chamber 9, conduits 8|] and 8| and chambers l8, moves rapidly into chamber 26.

As the weight of this mass of atmosphere |8, their diaphragms such as l9 promptly move under influence of atmosphere entering through theannular enlarged openings 4 I, and the brakes areapplied, thus the reservoir energy supply close at hand applies the brakes rapidly within its capacity if a full application is called for by the movement of lever l4, and deteriorates in proportion to the amount of air it absorbs from the brake applicators. At this point, and if a higher degree of vacuum energy is available from the manifold l5, which is usually the case, valves 33 and 34 close because of their unbalanced attitude, also by reason of the spring 42, which is much lighter than it was necessary to draw it. This closure against the seats 43 and 44 seals the auxiliary reservoir with the air it has stored diaphragms 36 and are balanced, valve 41 closes on seat 45, and stem 2'! being of sufficient length, causes valve 33, to leave its seat 43, permitting the surplus energy from manifold I5, to withdraw the air from the reservoir 2| and build up its vacuum to full manifold vacuum; this without in any wise interfering with the set brake application.

When the operator desires to release the brake application, by manipulating the control valve handle M to release position, full vacuum is restored in the control line 22. This causes the vacuum to be equal in chambers and 3|, thus relieving the diaphragm 36. Spring 51 returns said diaphragm and also plate and stem 31 to rest ,on stop 58. At the same time atmosphere in chamber 29 drives relay control diaphragm assembly 38 down away from seat against the underside of relay poppet valve 40, permitting atmosphere from chamber 29 and air cleaner to pass into chamber 9 and on into the brake power chambers, thus releasing the brake application. The special check valve VC known to the art as an open type check valve, is inserted in the conduit I l by its inlet 60 and to the relay instrument of the invention by outlet 6|. It embodies a chamber 62 and a diaphragm 63, supported by a light spring 641 The diaphragm is seatable against the annular valve seat 65, when a sharp inward rush of air, acting against the large area of the diaphragm B3, overcomes the spring 66, when, until conditions are changed, atmosphere is excluded from the relay through the conduit ll. Applying vacuum to conduit II will restore the valve to its normal state as it is shown in the figure.

When a breakaway occurs to a normally operae a j Invaouum brakes as practiced, the trailerre'servoirfurnishesran immediate, availabla-.sup-. plyl on energy, at I expense 01 its degree. oi:- s'tored energy; which inboth: reservoirand brake.

applicators will besubstantially less, than the,

original-degree-of vacuum, andtoget-a maximum brake-- application, which may. be and. often is. needed inthe shortestpossible time, the engine. must-pump both the reservoir and: the. brakeapplicators up tomaximum, which takesvaluable time. l

flow; by using the invention described, we canv use thestorageltank, as, before, for instantaneous, applications-and ther rby-pass it atv any-time. that a superior intensityof vacuum-is-available, go

on rrcm. there to maximum braking as desired and restore the storage tank, as it were at leisure.

Having fully described my invention so that an engineer familiar with vacuum brakes can construct and use it, what I claim as new and desire to secure by Letters Patent, is:

1. A vacuum brake relay valve comprising a body, flexible diaphragm walls therein forming boundaries of an atmosphere power chamber, at one end of said body, a control chamber opposite said atmosphere chamber spaced therefrom, rigid wall bounding a suction chamber, a brake operating chamber and an auxiliary reservoir chamber between said diaphragms, a lost motion valve tive brake system, both conduits 22 and II are consequently severed, the action is as follows:

When conduit ll, being normally at high vacuum, is severed, atmosphere pressure attempts to seek the vacuum in the trailer storage system, causing check valve VC to close as has been previously described. At the moment that the conduit 22 is severed, full atmospheric pressure is admitted to chamber 3|, thus causing a normal action of application to occur, except that the degree of application is limited to the capacity of reservoir to equalize the vacuum in the reservoir 2 I, and the applicators l9.

Thus it is seen that we first applied the brakes, instantaneously, with all of the power available in the storage tank; later, without having to await pumping a high vacuum in the storage tank, supplemented the brake application by direct energy from the manifold, and substantially increased the speed of arriving at the desired degree of brake application. Afterwards we were able to restore the storage tank, as it were at leisure, until its maximum energy was available, without in any way modifying the brake application. Should maximum brake application be desirable, later, an abundant supply of energy is available.

stem between said diaphragms with the lost motion parts arranged to abut upon contact by control, said suction chamber provided with inlet and opposite suction outlets, control valves on said outlets, the said valves being coaxial with r. and mounted on said valve stem, with the lost motion device between the said valves.

2. A vacuum relay valve for brakes comprising a body that encloses a suction chamber provided with two valved ports, an adjacent reservoir chamber, an atmosphere chamber, a control chamber, the atmosphere and control chambers being defined by flexible atmosphere and control diaphragms, a lost motion valve stem between said diaphragms, with the parts thereof within said suction chamber, a poppet brake operating valve on one of said suction chamber ports flexibly connected to one part of said stem to control power from said suction chamber, and a reservoir replenishing valve slidably mounted on said other suction chamber port and openable by excess available suction to replenish said reservoir after said first named valve has operated and reclosed.

3. A vacuum brake relay valve structure having in combination, a suction chamber, a vacuum reserve chamber, a brake operating chamber, valves for coordinating said chambers, opposed atmosphere and control diaphragm means for operating said valves, said valves seated on opposite sides of said suction chamber, valve seats therefor, a lost motion valve stem between said diaphragms and coaxial with said valves, one valve peing slidable on said stem, a coaxial pilot valve for said slidable valve, said pilot valve operable by said lost motion valve stem in response to high vacuum in said suction chamber.

4. The structure as claimed in claim 3 in which one of said valves is a mainbrake applying valve and the other said valve is for controlling communication between said suction chamber and said vacuum reserve chambenbeing formed as a composite valve with a pilot opening in the center thereof and a pilot valve normally spring urged to close said pilot opening.

5. A relay valve for vacuum brake control comprising a chambered body, opposed control and atmosphere diaphragms at opposite ends of said body, a valve stem therebetween, a lost motion device associated with said valve stem, a main suction chamber through which said valve stem passes, coaxial valve seats formed in walls of said suction chamber surrounding said stem, valves mounted for relative longitudinal movement on said stem to control said valve seats, one of said valves being a main brake applying valve and 10 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS I Price Oct. 14, 1947 

